ABSTRACT
This chapter focuses on the physical design aspects that affect the drivers' risk of falling, allowing recommendations for improvements to existing and new vehicles. There is a great deal of variation in the layout and the surfaces used in the 5th wheel area. Due to its position next to the diesel tank on the vehicle, the surfaces in the 5th wheel area tend to become contaminated with diesel. The surfaces used in covering the 5th wheel area (including battery unit) tend to be profiled metal or plastic surfaces. Pendulum and roughness data suggests that tail lifts offer a low slip potential in clean dry conditions. In wet conditions, tail lifts tend to present a high slip potential. The tail lifts which did offer satisfactory slip resistance in wet conditions were those which were older and had suffered more wear and scratching, increasing the surface microroughness.
